ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 219 PM EDT FRI JUL 25 2014 VALID 12Z TUE JUL 29 2014 - 12Z SAT AUG 02 2014 THE MEDIUM-RANGE MODELS AND ENSEMBLES CONTINUE TO HIGHLIGHT ANCHORING OMEGA BLOCKING COMPRISED OF SLOW MOVING AND UNSETTLING CLOSED MEAN LOWS CENTERED SOUTH OF THE WRN ALEUTIANS AND OVER THE GULF OF ALASKA THAT BOOKEND AN AMPLIFIED RIDGE EXTENDING NORTHWARD THROUGH THE CENTRAL ALEUTIANS TO ACROSS THE BERING SEA. THIS PATTERN FAVORS WRAPPING PCPN UP INTO THE W-CENTRAL ALEUTIANS WITH MODERATE AMOUNTS MORE LIKELY INTO COASTAL SRN AND SERN ALASKA TERRAIN. RIDGE AMPLITUDE MEANWHILE FAVORS SOME COOLING NRN STREAM TROUGHING AND GENERALLY LIGHT PCPN FROM THE ARCTIC DOWN INTO THE N-CENTRAL INTERIOR. THE 06 UTC GFS/GFS ENSEMBLE MEAN AND 00 UTC ECMWF AND ECMWF/NAEFS ENSEMBLE MEAN SEEM REASONABLY COMPATABLE AND OFFER GOOD CONTINUITY TO ALLOW WPC PREFERENCE FOR A COMPOSITE BLEND SOLUTION INTO DAY 6 THU. JUST THESE ENSEMBLES WERE UTILIZED AFTER THEN INTO DAY 8 IN A PERIOD OF GRADUALLY INCREASING DETERMINISTIC MODEL VARIANCE. THIS BLEND ALONG WITH SOME FORECASTER MODIFICATIONS MAINTAIN DECENT OCEANIC SURFACE LOW DEPTHS THROUGH THE PERIOD CONSISTENT WITH FAVORABLE DYNAMIC SUPPORT ALOFT. THIS BLEND ALSO PROVIDES SOME SMALLER SCALE DETAIL CONSISTENT WITH OTHERWISE ABOVE NORMAL PREDICTABILITY IN AN AMPLIFIED PATTERN WITH BELOW NORMAL FORECAST SPREAD. THIS BLEND WAS USED AS A BASIS FOR PRODUCTION OF THE ENTIRE WPC ALASKAN MEDIUM-RANGE FORECAST PRODUCT SUITE. THESE WELL CLUSTERED MODEL CHOICES REPRESENT SOLUTIONS ON THE SLIGHTLY MORE AMPLIFIED AND PERSISTENT SIDE OF THE FULL ENVELOPE OF SOLUTIONS CONSISTENT WITH THE BLOCKY PATTERN NATURE. SCHICHTEL